Jake in comments to this post asked about chambering the wrong ammo.
Here's the result of 5.56 into a 6.8 chamber. Notice it's not locked up? Firing pin can't reach the primer like this.
Here's 6.8 into a 5.56 chamber. It's even less locked up!
But if either one happens in combat, you're FUBAR.
ReplyDeleteIf that's the only ammo and mags you have, you sure are.
ReplyDeleteThe mags would have to be visually and tactilely distinct from each other. PRI puts horizontal ribs on their 6.8 mags; for example.
Making the guns distinct is more of a problem since except for the bolt and barrel it's a bog standard AR.
Like I said, it's not insurmountable, it's just a pain.
Good to know. Still, as Erin said, it would truly suck to find out in combat that you had accidentally grabbed one or more wrong magazines.
ReplyDeleteLike you said before, the transitional logistics would be the real nightmare. Imagine a unit with all 5.56 rifles getting a shipment of all 6.8 mags... just before deploying to Afghanistan.
Hopefully, it would be noticed BEFORE trying to get them to the field. The problem is when ammo resupply brings the wrong rounds, you can SEE they are wrong and they are useless to you. Now you have to wait for the next shipment and hope it's right.
DeleteThe magazine issue is bigger. At present there's no good way to tell them apart easily. 5.56 magazines will take about six 6.8 rounds before things go wrong. 6.8 mags will take 5.56 ammo, but are a lot more likely to "volcano" and spew ammo.
Additionally, the front rib is much shallower, that means the noses of the rounds are not aimed at the feed ramps, they try to "toe" out. Sometimes, it's fine, most of the time I get lots of double feeds.
DeleteAlso, how many people in combat, seeing that first situation, would waste time hitting the forward assist a couple of times? What kind of issues might that cause?
ReplyDeleteSorry, I'm not really familiar with the AR platform, so I might be asking silly questions.
The 5.56 into a 6.8 chamber is far enough along that pounding on the forward assist will smash things together but GOOD.
ReplyDeleteA 6.8 into the 5.56 chamber is too far open for the forward assist's pawl to engage in the bolt carriers grooves.
I'm not a fan of the forward assist. I'm not a fan of most of the immediate action drills I've seen.
Most problems in feed on an AR come from the mag. To my mind step one in any feed problem is lock it to the rear and ditch the mag. Then move on to fixing any remaining problems.
SPORTS is not the best plan. Slapping the bottom of the mag can cause a round to pop out. POR is basically racking the charging handle and hoping that whatever was wrong fixed itself. If it's a double feed, it makes it worse. T is tap the forward assist, making it more worse...
I like Lock, Ditch, Fidget, Load, Release.
That's lock it to the rear, ditch the mag, feel around the chamber area for rounds stuck in the gun, insert a new mag, hit the bolt release.
In case of a double, my way of doing it keeps you from shoving the loose round between the top of the upper and the gas tube.